Project summary The 2020 Gordon Research Conference on Sensory Transduction in Microorganisms to be held in Ventura, CA will explore recent advances in understanding signal transduction in bacteria, especially pathogens. Focus will be placed on chemosensory and quorum sensing mechanisms and pathways, small molecule intracellular signals (e.g. c-di-GMP and other cyclic nucleotides, ppGpp), two component systems and the cellular processes they regulate as well as mechanisms of bacterial lifestyle decisions including biofilms, bacterial multicellular behavior and predator-prey interactions. The roles of these systems with respect to pathogenesis and antimicrobial resistance will be central themes. A newly designed topic for this conference will be host- microbe interactions including the interplay between bacterial second messengers and the host immune system. All these critical areas will be addressed through cutting-edge applications of molecular genetics, cell biology, biochemistry, and chemical biology as well as structural, imaging, biophysical, and computational approaches. Data from high-resolution experiments will be paired with modeling to understand and predict the behavior of complex macromolecular assemblies and signaling circuitry. Invited speakers will include both established and early-stage investigators. In addition, poster presenters will compete for short talks. Participants will benefit from the Conference's open, collegial atmosphere that provides unique opportunities to engage in scientific discussion, promote scientific rigor, and foster interdisciplinary collaboration. For the third time, a Gordon Research Seminar (GRS) for postdocs and graduate students will precede the GRC. The GRS provides a supportive environment for young scientists to present their work and receive advice by leaders in the field. The STIM community has long supported junior scientists, and we view the success of the GRS as a necessity to continue on this mission. The GRS will help us not only nurture the development of early stage investigators, but also promote diversity within our community. The GRS will help junior scientists gain the confidence and skills to become full-fledged GRC participants. The well-integrated STIM GRC/GRS will direct established investigators to the most important questions confronting our field and will encourage young scientists to apply their recent training to the exciting new areas of microbiology.